General Knowledge - Physics - Discussion
Discussion Forum : Physics - Section 1 (Q.No. 57)
57.
On a stationary sail boat, air is blown from a fan attached to the boat. The boat
Discussion:
59 comments Page 4 of 6.
Sid said:
1 decade ago
The weight of the boat is not mentioned. In a water surface the friction is approximately zero. So according to newton's 3rd law the boat must move.
Ajay said:
1 decade ago
Becouse every action there is equal and opposit reaction. So for movement of a body there is need of reaction, which is not available to boat becouse fan is monted on boat itself.
Shiyas said:
1 decade ago
The boat will move!!!If sufficient thrust is produced.
Shiyas said:
1 decade ago
This case is similar to propeller aircraft in which the propeller is mounted on the aircraft.when propeller turns air is blown and as the momentum of air changes it imparts reaction on the blades of the propeller,which in turn moves the air craft.
Amit said:
1 decade ago
I agree with Shiyas, It will definitely move if force is enough.
Banshi dhar said:
1 decade ago
I totally disagree with amit and shiyas because the force [thrust] acts on a body[boat] in a perpendicular direction.
Jyoti said:
1 decade ago
Please suggest a particular reason for no motion.
ANOOP C RAJ said:
1 decade ago
Air is less denser than water. So large fan is needed. Otherwise it must be a hovercraft.
Ramanuj said:
1 decade ago
The boat will move. The air which is propelled by the fan will give an equal and opposite reaction/force to the fan and the fan will tend to move and as the fan is attached to the boat the boat will tend to move. If this force is more than the threshold force to move the boat the boat will definitely move in a direction opposite to the motion of the air. This simple principle is used in aeroplanes where the air is heated to get more thrust.
Sudha said:
1 decade ago
Theoritycally the boat should move(whatever be the thrust).
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers